The Economic and Environmental Significance of Nonpoint Source Abatement in Large Watersheds

Throughout the United States, nonpoint source pollution from stormwater runoff, failing septic tanks and other diverse sources is a significant, often dominant, cause of noncompliance with water quality standards in large watersheds. Even with this knowledge, considerable economic resources are spent on reduction of conventional point source pollution (e.g., wastewater discharges and combined sewer overflows) with little more than a casual understanding of the nonpoint source pollution sources within a large watershed, or of the potential value of dollars spent, as measured by improvements in receiving water quality or designated use attainability. This work shows that quantification of nonpoint sources and their influence on regulatory compliance should be at the forefront of watershed management efforts, not as a replacement for point source abatement, but as a factor worthy of equivalent scientific and economic attention. With this guiding principle, this work illustrates how abatement costs and resulting environmental improvements for both point and nonpoint source controls must be clearly understood and managed together if the fundamental precepts and objectives of the Clean Water Act are to be addressed decisively.